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Biomedical subjects

G F Anderson

Publications and source records attributed to G F Anderson.

At least 55 records · Page 3Linked to original sources

What does not explain the variation in the direct costs of graduate medical education.

BACKGROUND: There is considerable variation in the costs of training residents across hospitals. Previous studies have reported training costs that ranged for $7,500 to $200,000 per resident, with means in the $50,000 to $60,000 range. This paper examines the factors associated with the variation in the direct costs of residency education across hospitals. METHODS: Hospital costs, hospital payment rates, various cost-of-living indices, and hospital characteristics for all hospitals in the United States receiving Medicare funds for residency education in fiscal year 1991 were obtained from various public sources. Bivariate and multivariate analyses were performed to determine whether organizational structure of residency training, specialty mix of residents, quality of training, cost of living in the geographic area, patient mix of the hospital, or other factors could explain some or all of the cost variation. RESULTS: Only a small proportion of the variation in the costs of training residents or payments for residency education could be explained by the factors analyzed. CONCLUSION: Much of the current variation in residency costs and payments is attributable to accounting and not structural or locational factors. Institutions looking for ways to become more efficient could compare costs of training across institutions without sophisticated adjusters. Federal policymakers should consider a national payment rate per resident to replace the current system based on hospital-specific costs. This proposal would redistribute dollars across residency programs. The proposal would affect payments for direct medical education in the Medicare program and could form the basis for payment for residency education by all payers.

Accounting↗

Risk of retinal detachment following cataract extraction: results from the International Cataract Surgery Outcomes Study.

AIMS: To estimate the risk of retinal detachment (RD) following cataract extraction in Denmark, and to compare the risk with that following cataract extraction in the USA, and with that in a sample of Danish patients who did not have ocular surgery. METHODS: A sample was created from the administrative Danish Hospital Register and included 19,252 patients who underwent first eye cataract surgery between 1985 and 1987, and who were 50 years of age or older. The patients were then followed for 4-6 years using the register data. The design and definition of events were identical to the US National Study of Cataract Outcomes. RESULTS: In Denmark a 4 year cumulative risk of hospitalisation for RD of 0.93% (95% confidence interval (CI) 0.71-1.16) was observed following an extracapsular cataract extraction with a lens implant. A similar cumulative risk of RD was reported from the US study. Thus, no difference in outcomes concerning risk of RD was shown between Denmark and the USA. In a multivariate analysis younger age, male sex, and intracapsular cataract extraction were all associated with higher risk of postoperative RD. A reference group of 7636 people not undergoing any ocular surgery was created and the incidence of RD in this group was calculated. During the sixth year following cataract surgery, the incidence of RD in the cataract group was still 7.5 (95% CI 1.6-22.0) times higher than that observed in the reference group.

Age Factors↗

Hospital employment trends in California, 1982-1994.

During the 1980s California hospitals responded to selective contracting, growth in managed care, and the Medicare prospective payment system (PPS) by controlling their level of spending. This DataWatch examines whether these hospitals achieved these savings by changing the number and/or the mix of hospital employees. We examined employment trends because wages represent the largest component of hospital budgets and because the number and mix of personnel can be changed in the short run. Analysis of the California Health Facilities Cost Report data shows that employment increased steadily during 1982-1994. There is no evidence that hospitals responded to growing competition by altering the rate of growth in hospital personnel and only weak evidence that they altered the mix of personnel by hiring a greater proportion of nonclinical staff. We conclude that increased competition had only a minor effect on hospital employment decisions.

California↗

Risk-adjusted Medicare capitation rates using ambulatory and inpatient diagnoses.

Researchers at The Johns Hopkins University (JHU) developed two new diagnosis-oriented methodologies for setting risk adjusted capitation rates for managed care plans contracting with Medicare. These adjusters predict the future medical expenditures of aged Medicare enrollees based on demographic factors and diagnostic information. The models use the Ambulatory Care Group (ACG) algorithm to categorize ambulatory diagnoses. Two alternative approaches for categorizing inpatient diagnoses were used. Lewin-VHI, Inc. evaluated the models using data from 624,000 randomly selected aged Medicare beneficiaries. The models predict expenditures far better than the Adjusted Average per Capita Cost (AAPCC) payment method. It is possible that risk adjusted capitation payments could encourage health plans to compete on the basis of efficiency and quality and not risk selection.

Aged↗

Capitation adjustment for pediatric populations.

OBJECTIVE: The objective of this study is to assess the predictive performance of current claims-based capitation adjustment methods for pediatric populations. Medicaid programs and other insurers may increasingly use these systems for capitation rate setting, physician profiling, and other purposes. METHODS: Five leading models, a demographic model, ambulatory care groups, ambulatory diagnostic groups, diagnostic cost groups, and payment amounts for capitated systems, were tested by using use and expenditure data for children enrolled in the Maryland Medicaid program and a private nonprofit health maintenance organization in Minnesota. The models were tested at the individual level by using multiple regression methods and at the group level by using split-half validation to create both random and nonrandom groups. One of the nonrandom groups was created to represent children with chronic conditions. RESULTS: The findings indicate that although each of the alternative methods offers an improvement over a demographic model, significant underpayment remained for high-risk children, regardless of the capitation adjustment method used. CONCLUSIONS: It is concluded that children with chronic conditions would probably remain at risk for discrimination in a competitive health care market under all models tested. Limitations associated with current alternatives suggest the need for further research in the area of pediatric capitation adjustment methods.

Adolescent↗

Employment trends in hospitals, 1981-1993.

This paper examines trends in hospital employment from 1981 to 1993. After controlling for changes in the inpatient and outpatient volume and using a proxy for changes in case mix, the number of hospital employees increased steadily during this period. Most of the growth occurred in the nonclinical areas. There was no statistically significant difference in the employment growth in states with high or low penetration of health maintenance organizations (HMOs), or in states with and without all-payer rate-setting programs, suggesting that neither competitive nor regulatory programs influenced employment trends in the hospital industry.

Allied Health Personnel↗

Characterization of muscarinic receptors in the rat nucleus tractus solitarius.

Crude membrane preparations from the dorsomedial medulla and whole heart of adult rats were used to characterize muscarinic receptors (mChRs) in the nucleus tractus solitarius (NTS). Isotherm binding assays with [3H]quinuclidinyl benzilate ([3H]QNB) indicated a uniform population of muscarinic cholinergic receptors in both tissues with a Kd of 60.3 pM and a Bmax of 401 fmol/mg protein for NTS membranes while heart membranes had a Kd of 56.6 pM and a Bmax of 193 fmol/mg protein. Competitive binding assays with selective muscarinic antagonists on NTS membranes using 80 pM [3H]QNB showed the following relative Ki values consistent with M2 mChRs: atropine, 1.9 nM; methoctramine, 7.7 nM; 4-diphenylacetoxy-N-methylpiperidine methobromide, 9.4 nM; AF-DX 116, 87.6 nM; and pirenzepine, 657 nM. Similarly, two agonists, carbachol and oxotremorine, showed Ki values of 1.82 microM and 0.379 microM, respectively. All of the competitive binding assays exhibited Hill coefficients close to 1.0 and InPlot analysis showed a single binding site for each agonist and antagonist examined.

Animals↗

Presynaptic displacement of serotonin by alpha-methyl-5-hydroxytryptamine in the nucleus tractus solitarius of the rat.

Rat brain slices containing the nucleus tractus solitarius loaded with [3H]5-hydroxytryptamine ([3H]5-HT) for superfusion were stimulated at (3 Hz, 25 mA, 1 min) resulting in fractional release ratios S2/S1 of 0.89 for [3H]5-HT in the presence of the serotonin uptake inhibitor 1.0 microM 6-nitroquipazine (6-NQ). alpha-Methylserotonin (alpha-Me-5-HT; 1.0 microM), a non-selective 5-HT1 and 5-HT2 receptor agonist, significantly reduced the S2/S1 ratio of [3H]5-HT without affecting the basal release ratios B2/B1 1.00 +/- 0.04. Without 6-NQ in the perfusion medium 1.0 microM alpha-Me-5-HT sharply increased the basal release B2/B1 to 2.21 (P < 0.01). In low Ca2+ medium the S2/S1 ratio was reduced to 0.06 and alpha-Me-5-HT promoted a B2/B1 release of 2.17 (P < 0.01). The 5-HT3 antagonist LY-278,584 did not block alpha-Me-5-HT induced basal release of [3H]5-HT. Both pindolol and LY-53,857 blocked the autoinhibitory effects of alpha-Me-5-HT, but only LY-53,857 and 6-NQ blocked the basal release induced by alpha-Me-5-HT. These results suggest that alpha-Me-5-HT reduces neurotransmitter release through the serotonin autoreceptor and displaces serotonin through a non-exocytotic release mechanism.

Animals↗

Displacement of norepinephrine by alpha-methylnorepinephrine in the nucleus tractus solitarius of the rat.

Rat brain slices from the dorsomedial medulla containing the nucleus tractus solitarius were loaded with [3H]norepinephrine ([3H]NE) for superfusion. Electrical stimulation (3 Hz, 25 mA, 1 min) resulted in fractional release ratios S2/S1 of 0.97 +/- 0.02 in normal Krebs-Henseleit (KH) and 0.93 +/- 0.06 in the presence of 30 microM cocaine. With cocaine in the KH medium, L-alpha-methylnorepinephrine (alpha-MeNE) significantly reduced the [3H]NE release S2/S1 without affecting the basal release ratios. Without cocaine in the KH medium both 0.1 and 1.0 microM alpha-MeNE increased the basal release B2/B1 that was not affected by yohimbine. Prazosin had no effect on the S2/S1 ratio but did attenuate the basal release effects of alpha-MeNE. In low Ca2+ studies where the S2 stimulus was abolished, 1.0 microM alpha-MeNE induced a sharply elevated increase in the B2/B1 ratio. It appears that alpha-MeNE in the presence of the uptake inhibitors reduces presynaptic neurotransmitter release through alpha 2-adrenoceptors, whereas when uptake of the monoamines was not blocked alpha-MeNE was considerably more efficacious as a displacing agent of neurotransmitter.

Animals↗

Economic impact of immunization against rotavirus gastroenteritis. Evidence from a clinical trial.

OBJECTIVE: To estimate the economic impact of immunization against rotavirus gastroenteritis in an infant population in the United States. DESIGN: Cost identification and break-even analyses from the perspective of society, nested within a phase 3, randomized, double-blind, placebo-controlled trial. PATIENTS: Infants (N = 1278), aged 6 to 22 weeks, enrolled during the summer and fall of 1991 and followed up until July 1, 1992. INTERVENTION: Immunization schedule of three doses of orally administered tetravalent or serotype 1 rhesus rotavirus vaccine, or placebo. MAIN OUTCOME MEASURES: Incidence of rotavirus gastroenteritis, total direct medical costs, direct nonmedical costs, and indirect costs of rotavirus and nonrotavirus gastroenteritis for the duration of the study and of any illness during 5 days after each dose. The cost of the vaccine was not included. RESULTS: Median total cost per infant among the 1187 infants who completed the immunization schedule was $9 in the tetravalent vaccine group, $9 in the serotype 1 vaccine group, and $49 in the placebo group (P = .01). Rotavirus gastroenteritis occurred in 195 infants (16%): 13% (51/398) in the tetravalent group, 12% (47/404) in the serotype 1 group, and 25% (97/385) in the placebo group (P < .0001). Of infants with an episode of rotavirus gastroenteritis, the proportion who incurred cost during the episode and the median cost during the episode did not differ by treatment group. The baseline net cost savings for treatment of rotavirus gastroenteritis and break-even cost of immunization were $11 per infant for the tetravalent vaccine and $12 for the serotype 1 vaccine. In sensitivity analysis, savings ranged from $40 to -$6, because of a large variance in the costs of rotavirus gastroenteritis. CONCLUSION: The results of the baseline analysis suggest that society should be willing to pay between $11 and $12 for immunization against rotavirus. It might be willing to pay an additional amount for the intangible benefits of reduced parental inconvenience or anxiety associated with this illness in infants.

Cost Savings↗

Uncertain demand, the structure of hospital costs, and the cost of empty hospital beds.

In this paper we reformulate the theory of cost and production to take account of uncertain demand facing a firm. In the reformulated theory the duality between cost and production no longer obtains, and demand distribution parameters enter the cost function as well as the traditional outputs and input prices. We then estimate a short run cost function for a hospital facing uncertain demand using data from a national sample of over 5000 hospitals for the years 1983-1987. The traditional cost model is strongly rejected in favor of the reformulated model. This model is used to calculate the cost of empty hospital beds, controlling for the effect of uncertain demand on the structure of hospital costs. The cost of an empty hospital bed is calculated as $36,443 in 1987 dollars. We estimate that a one percent decrease in the number of hospital beds would decrease hospital costs by slightly over one-third of one percent. Increasing the occupancy rate from the average 1992 level (65 percent) back to the average 1980 level (76 percent) is estimated to save the average hospital over $2 million, or 9.5 percent of costs.

American Hospital Association↗

Evidence for presynaptic adenosine A2a receptors associated with norepinephrine release and their desensitization in the rat nucleus tractus solitarius.

Rat medullary brain segments containing primarily nucleus tractus solitarius (NTS) were used for superfusion studies of evoked transmitter release and for isotherm receptor binding assays. Isotherm binding assays with [3H]CGS-21680 on membranes prepared from NTS tissue blocks indicated a single high-affinity binding site with a KD of 5.1 +/- 1.4 nM and a Bmax of 20.6 +/- 2.4 fmol/mg of protein. The binding density for [3H]CGS-21680 on NTS membranes was 23 times less than comparable binding on membranes from striatal tissue. Electrically stimulated (1 min at 25 mA, 2 ms, 3 Hz) release of [3H]norepinephrine ([3H]NE) from 400-microns-thick NTS tissue slices resulted in an S2/S1 ratio of 0.96 +/- 0.02. Superfusion of single tissue slices with 0.1-100 nM CGS-21680, a selective adenosine A2a receptor agonist, for 5 min before the S2 stimulus produced a significant concentration-dependent increase in the S2/S1 fractional release ratio that was maximal (31.3% increase) at 1.0 nM. However, superfusion of tissue slices with CGS-21680 over the same concentration range for 20 min before the S2 stimulus did not alter the S2/S1 ratio significantly from control release ratios. The augmented release of [3H]NE mediated by 1.0 nM CGS-21680 with a 5-min tissue exposure was abolished by 1.0 and 10 nM CGS-15943 as well as by 100 nM 8-(3-chlorostyryl)caffeine, both A2a receptor antagonists, but not by 1.0 nM 8-cyclopentyl-1,3-dipropylxanthine, the A1 receptor antagonist.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗

Effect of insulin and clonidine on the evoked release of norepinephrine and serotonin from the nucleus tractus solitarius of the diabetic rat.

Dorsal medullary brain slices containing primarily the nucleus tractus solitarius (NTS) were obtained from normal or 40- to 50-day streptozotocin-diabetic rats and employed for superfusion studies of evoked transmitter release. Electrically stimulated (25 mA, 2-ms pulses, 3 Hz, 1 min) release of [3H]norepinephrine ([3H]NE) or [3H]5-hydroxytryptamine ([3H]5-HT) from 400-microns NTS slices stimulated at 75 min (S1) and 130 min (S2) resulted in S2/S1 release ratios that were not different between normal controls or diabetic control groups. Perfusion of normal [3H]NE-loaded slices with 0.1 mumol/l clonidine reduced the S2/S1 ratio by 23% (p < 0.05) which was uniform in the caudal, subpostremal, and intermediate segment levels of the NTS. In diabetic NTS slices, the S2/S1 ratio was significantly less reduced by clonidine in both the subpostremal (-3%) and intermediate (-11%) slice regions. Blockade of alpha 2-adrenoceptors with yohimbine (0.1 mumol/l) enhanced (p < 0.05) [3H]NE release (S2/S1 ratios) in slices from both normal and diabetic rats. Perfusion of [3H]NE-loaded slices with 5 mU/ml insulin did not affect S2 release. Evoked S2/S1 release ratios from NTS slices loaded with [3H]5-HT did not differ between normal control and diabetic control groups. Clonidine (0.1 mumol/l) reduced S2-evoked release in both normal (-30%) and diabetic (-44%) slices, but the groups were not different from each other. Superfusion with 5 mU/ml insulin did not alter S2/S1 ratios in normal [3H]5-HT loaded slices, but did increase the diabetic NTS slice S2/S1 ratio to 1.40 +/- 0.06 (p < 0.01). In summary, it appears that alpha 2-adrenoceptor-mediated inhibition of [3H]NE release in the NTS was selectively attenuated in a regionally specific manner in diabetic animals. Release inhibition may be associated with receptor downregulation in NTS regions associated with cardiovascular reflex transmission. Insulin superfusion augmented [3H]5-HT release in the diabetic NTS slices, possibly through increased transmitter synthesis or improved synaptic release.

Adrenergic alpha-Agonists↗

The relationship of provider organizational status and erythropoietin dosing in end stage renal disease patients.

Controversy exists as to whether provider organizational characteristics such as profit status and setting are associated with the content of medical care or efficiency with which care is rendered. Following FDA approval of human recombinant erythropoietin (EPO) for use in clinical practice, Medicare approved coverage for beneficiaries in its end stage renal disease program and established a fixed payment per dose. Because cost of EPO administration varied positively with dose, providers could realize larger profit with prescription of smaller doses. We used Medicare claims data to assess EPO use by renal dialysis providers one year after FDA approval (June 1990) as a function of provider ownership (for-profit, not-for-profit, government agency) and setting (hospital-based, free-standing). Mean dose of EPO was 236 units greater (P = 0.0001) for not-for-profit freestanding facilities, 593 units greater (P = 0.0001) for government facilities, and 555 units greater for not-for-profit hospitals (P = 0.0001) than among for-profit freestanding providers. With fixed payment per dose of EPO, for-profit, freestanding providers prescribed EPO more often and administered smaller doses than not-for-profit or government providers, behavior that is consistent with profit maximization.

Ambulatory Care Facilities↗

Analyzing health outcomes through international comparisons.

There is increasing interest in the conduct of international studies that compare health care outcomes. This paper draws from the literature in sociology, anthropology, and psychology to examine the problems that can be encountered when collecting primary data for comparative purposes. Issues of study design, selection, development, and adaptation of instruments, problems encountered in collecting primary data, and techniques for analyzing comparative data are discussed. The paper is intended as a primer for health services researchers conducting comparative outcomes research in international settings.

Data Collection↗

Effect of recombinant erythropoietin on hospital admissions, readmissions, length of stay, and costs of dialysis patients.

To examine the effects of recombinant human erythropoietin (rHuEPO) on hospital utilization, hospital costs, and Medicare reimbursements for hospital care, a longitudinal, matched cohort study was conducted using Medicare claims data of 23,806 Medicare-eligible, dialysis patients who received rHuEPO, did not have a transplant, and were alive for 18 mo or longer and 22,720 controls matched on age, sex, race, cause of ESRD, and dialysis modality. The relative odds (rHuEPO versus control) of admission for all causes and for specific causes over 9 mo, adjusted for admission in the prior 9 mo and the per patient change in total admissions, inpatient days, hospital costs, and Medicare hospital payments between the prior 9-mo period and the subsequent 9-mo period was examined. The adjusted relative odds (95% confidence interval) of admission (rHuEPO versus control) was: higher and statistically significant for all causes, 1.08 (1.03 to 1.14); seizure, 1.52 (1.28 to 1.75); vascular access revision, 1.11 (1.06 to 1.17), and heart failure, 1.17 (1.09 to 1.26); higher but not statistically significant for angina, 1.09 (0.99 to 1.20) and stroke, 1.08 (0.86 to 1.31); and lower but not statistically significant for myocardial infarction, 0.91 (0.72 to 1.10); peripheral vascular disease, 0.81 (0.60 to 1.02); anemia, 0.86 (0.56 to 1.17); and depression, 0.89 (0.37 to 1.40). The mean change per 1,000 patients in admissions was less by 38 (P = 0.03) because of fewer readmissions, and in days was 1,309 less (P < 0.001), for patients treated with rHuEPO versus controls. The mean change per patient in hospital costs was $371 less and was statistically significant (P = 0.03) and in Medicare hospital payments was $132 less but was not statistically significant (P = 0.43) for patients treated with rHuEPO versus controls. rHuEPO was associated with an increase in the probability of hospital admission (particularly admissions potentially related to adverse effects) but a decrease in readmissions, overall admissions, hospital days, and cost to hospitals in this cohort of patients surviving for 18 mo. Although not realized short term, Medicare savings from potential rHuEPO-related reductions in hospital care may be long term through future adjustments in diagnosis-related group-based hospital payment.

Adult↗

A review of the first year of Medicare coverage of erythropoietin.

Recombinant human erythropoietin (rHuEPO) is a new drug for treating anemia associated with end stage renal disease (ESRD). In a study of rHuEPO diffusion, costs, and effectiveness, we analyze ESRD program data and all claims submitted to Medicare for reimbursement of rHuEPO administered to ESRD dialysis patients. Access to rHuEPO was rapid and extensive during the first year of Medicare coverage. Dosing of rHuEPO and achieved hematocrit were lower than expected based on the results of clinical trials. rHuEPO cost Medicare $144 million in its first year. The analysis of insurance claims data allowed effective monitoring of access, costs, and effectiveness of this new biotechnology.

Black or African American↗